package com.fly.core.hash;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.codec.binary.Hex;

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class SHA256
{
    /***
     * 
     * 利用Apache的工具类实现SHA-256加密
     * 
     * @param str 加密后的报文
     * @return
     * 
     */
    public static String getSHA256Str(String str)
    {
        MessageDigest messageDigest;
        String encdeStr = "";
        try
        {
            messageDigest = MessageDigest.getInstance("SHA-256");
            byte[] hash = messageDigest.digest(str.getBytes("UTF-8"));
            encdeStr = Hex.encodeHexString(hash);
        }
        catch (NoSuchAlgorithmException | UnsupportedEncodingException e)
        {
            log.error(e.getMessage(), e);
        }
        return encdeStr;
    }
    
    /**
     * 
     * 利用java原生的摘要实现SHA256加密
     * 
     * @param str 加密后的报文
     */
    public static String getSHA256StrJava(String str)
    {
        MessageDigest messageDigest;
        String encodeStr = "";
        try
        {
            messageDigest = MessageDigest.getInstance("SHA-256");
            messageDigest.update(str.getBytes("UTF-8"));
            encodeStr = byte2Hex(messageDigest.digest());
        }
        catch (NoSuchAlgorithmException | UnsupportedEncodingException e)
        {
            log.error(e.getMessage(), e);
        }
        return encodeStr;
    }
    
    /**
     * 
     * 将byte转为16进制
     * 
     * @param bytes
     * @return
     * 
     */
    private static String byte2Hex(byte[] bytes)
    {
        StringBuffer stringBuffer = new StringBuffer();
        String temp = null;
        for (int i = 0; i < bytes.length; i++)
        {
            temp = Integer.toHexString(bytes[i] & 0xFF);
            if (temp.length() == 1)
            {
                // 1得到一位的进行补0操作
                stringBuffer.append("0");
            }
            stringBuffer.append(temp);
        }
        return stringBuffer.toString();
    }
}